Herbert James Gunn was born in Glasgow and studied at both the Glasgow School of Art and Edinburgh College of Art before progressing to the Académie Julian in Paris, where he continued his education under Jean-Paul Laurens. He exhibited mainly at the Royal Academy, the Royal Scottish Academy, and the Paris Salon.

In 1929, Gunn returned from Rome, where he and his wife had been living, to be present at his show of Italian landscapes, which was held at The Fine Art Society in London. In a melancholy letter to his wife at the end of the show, he explained that he had not sold one painting and he was unable to make a living as a landscape painter. He then turned to figurative paintings and portraits, and as a result gained a national reputation as a society portrait painter, and was later knighted for his success.